Question

How many of the statement(s) are correct

i) The nucleophile makes a rear attack in ${\text{S}}_{\text{N}}\text{2}$ reaction and expels the leaving group from front side.

ii) $C{H}_{3}O-CH=C{H}_2$ adds to $\text{HBr}$ according to Anti‐Markownikoff’s rule.

iii) The basicity of halides decreases in the order $F^{-}>C{1}^{-}>B{r}^{-}>I^{-},$ but the nucleophillicity is reverse of it. (in polar protic solvents)

iv) The rate of ${\text{S}}_{\text{N}}\text{2}$ reaction is independent of the polarity of the solvent.

v) Sigma complex or arenium ion is resonance stablised.

Answer 1

Answer: 3

i) The nucleophile makes a rear attack in ${\text{S}}_{\text{N}}\text{2}$ reaction and expels the leaving group from front side.

iii) The basicity of halides decreases in the order $F^{-}>C{1}^{-}>B{r}^{-}>I^{-},$ but the nucleophillicity is reverse of it. (in polar protic solvents)

v) Sigma complex or arenium ion is resonance stablised.

The above statements are correct.

$C{H}_{3}O-CH=C{H}_2$ adds to $\text{HBr}$ according to Markownikoff’s rule.

iv) The rate of ${\text{S}}_{\text{N}}\text{2}$ reaction is faster in polar aprotic solvent.